The K23 candidate (Dr. Elder) has recently advanced to a junior faculty positioning the Department of Pediatrics, Division of Endocrinology. This award will provide the candidate with scholarly training, mentorship, and support necessary to develop into an independent clinical researcher executing state of the art metabolic testing of beta-cell function in adolescents with type 2 diabetes. Specific objectives are to 1) develop expertise in the study and understanding of pancreatic a-cell function and its role in the development of diabetes in children and adolescents and 2) Become an independent and externally funded investigator in diabetes research. To achieve these career objectives, the candidate proposes a five-year training program with faculty members from a strong pediatric department and affiliated medical school. Her primary sponsor is a very experienced researcher whose work has focused on the study of pancreatic beta-cell function in adults with type 2 diabetes. Her co-mentor is the Director of the Diabetes Center with vast experience in recruitment and retention of pediatric patients with diabetes His work has focused on the epidemiologic aspects of diabetes in youth and aspects of cardiovascular risk associated with obesity. The candidate's proposed research involves two projects: 1) Specific aim 1. will define the natural history of a-cell function in adolescents with type 2 diabetes by characterizing the first phase insulin response to intravenous glucose and the insulin response to intravenous arginine diagnosis, 6 months and annually over 3-4 years in 30 adolescents with type 2 diabetes; 2) Specific aim 2. will determine whether adolescents with type 2 diabetes share the defects in insuiln secretion that typify adult diabetic patients such as beta-cell sensititivty to glucose, a decrease in functional a-cell mass, and an impaired incretin effect.